Yum Brands Inc.(YUM), the parent company of KFC, only made the sandwich available temporarily before yanking it off the market.

"KFC sold more than 10 million in the first month when Double Down launched in 2010," Maynard said." As a result of that popularity, the product remained on the menu past the end of the original promotional period."

Back in 2010, Yum Brands Chief Financial Officer Rich Carucci referred to the sales as having an "immaterial" impact for the overall company.

Double Down may be following in the popular footsteps of McDonald's(MCD) Shamrock Shake, a neon green frozen drink that spurs a sales frenzy when it's offered seasonally.